Technology and energy management hand in hand.

Wort boiling with the JETSTAR™:

engineering for a better world GEA Process Engineering

2

In wort boiling a comprehensive approach pays off.

In order to achieve optimal results in the hot phase in

the brewhouse, all processes and energy management

need to be considered as one entity. This is precisely what

GEA Brewery Systems does. We see state-of-the-art wort

boiling as an interrelated package comprising the heating

External wort preheatingWhen using an energy storage system, the wort is gently heated to boiling temperature via an external plate heat exchanger. Compared to heating with a conventional internal boiler, this process protects the high-molecular foam-positive nitrogen and considerably reduces the thermal stress, which benefits the flavour stability of the beers produced with this technique.

Wort boiling – a comprehensive process

1

2

3

Whirlpool

Wort kettlewith JETSTAR™

process 1 , the actual wort boiling 2 and the wort

treatment 3 during cast-out. Each individual step has a

decisive impact on the next one and each step contributes to

the overall optimization of the process in terms of outstanding

beer quality and high efficiency.

Returnenergy storage

Fromenergystorage

From wortpre-run tank

Condensate

Wort cooler

Wortheater

Energy storageWort

Warm water

Cold water

Wort aeration

To the fermenting room

Vapourcondenser

3

Technical solutions to match all requirements.

Gentle pre-cooling, less DMSThe DMS concentration in the finished product can be significantly reduced by wort pre-cooling during cast-out. This is achieved using a separate small plate heat exchanger or by cooling down a partial wort flow with the existing wort cooler. This process does not affect the warm water balance of the brewhouse.

Vapour condenserEnergy recovery systems in the brewhouse are applied where most thermal energy is consumed in the brewery: during wort boiling. Apart from the start-up and shutdown quantities, which are technically unavoidable, the vapour condenser also significantly reduces vapour emissions.

GEA Brewery Systems offers the entire range of

wort boiling options to perfectly meet the different

requirements of breweries. We have decades of experience

in the construction of boiling systems, for atmospheric

pressure boiling as well as for low-pressure boiling. From

energy storage systems to vapour compression units and

combined Whirlpool/wort kettles GEA Brewery Systems

can offer suitable solutions that are state-of-the-art. For any

type of brewhouse and for any type of beer.

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Dynamic, with maximum flexibility.

GEA Brewery Systems has developed the low-pressure

boiling system to a level suitable for practical application.

We have consistently advanced this technology and

developed the Dynamic Low-Pressure Boiling system

(Dyn. LPB). Today we combine atmospheric boiling as well

as Dynamic Low-Pressure Boiling with the JETSTAR ™, a

novel internal boiler system with a unique flow pattern.

With this innovative internal boiler we managed to

completely redesign the wort boiling process. Due to the

Subjet – an adjustable opening below the wort surface –

wort boiling is becoming more flexible and the process can

be controlled even more accurately. During wort heating,

the Subjet is open and the wort flows back into the wort

kettle below the wort surface. Without counterpressure

the circulation rate of the internal boiler increases and

wort homogeneity in the kettle is improved, which reduces

thermal stress during heating.

A more dynamic processThe advantage of the Dyn. LPB is the even faster evaporation of undesired aromas due to the intensive boiling in intervals. As soon as the predetermined pressure is reached, a systematic pressure reduction starts under strictly defined conditions. As pressure is reduced, the boiling temperature in the vessel

decreases accompanied by a rapid steam bubble formation throughout the entire kettle. This “controlled boiling delay” results in a very large gas/liquid contact surface thus ensuring an optimum stripping of volatile aromas.

Pressure build-up Pressure relief

DepressurizingCast-out

Time [min]

Overpressure[mbar]

Phase 1Filling Heating

Phase 2

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Phase 1 – Thermal conversion

At the beginning of the boiling process the Subjet stays

open. Then, a boiling phase with an extremely low

evaporation rate follows, however, offering the possibility

to individually influence the temperature-dependent

reactions, such as hop isomerization, protein coagulation,

reduction of undesirable odorous substances and formation

of important flavour components, via the time parameter.

High circulation rates at low steam pressure preserve the

foam-positive substances in the wort.

The perfect mixing of the kettle content ensures a

homogeneous wort temperature.

Phase 2 – Evaporation

For the evaporation phase the lower Subjet opening is now

closed. By adjusting the steam pressure, the evaporation

rate is increased to the necessary value and the wort

circulates via the two-level wort deflector. The large

surface area thus created ensures an intense evaporation

of undesired aromas. Due to the extensive reduction of the

DMS precursor in phase 1, a comparably low evaporation

rate is sufficient to achieve the desired final content of free

DMS and other flavour components in the cast-out wort.

This two-phase wort boiling process is not only suitable for

atmospheric kettles, but can also be combined with Dynamic

Low-Pressure Boiling (as shown here).

Improved wort homogeneity in the kettleImplementing the JETSTAR ™ results in a substantial improvement of the mixing process in wort kettles with internal boiler. Due to an increased impulse exchange the usual short circuit flows are almost completely eliminated and temperature distribution is improved. The more homogeneous temperature distribution accelerates conversion processes. The chart illustrates the comparison of DMS-P degradation between a conventional internal boiler and a JETSTAR ™, which reduces the half life of the DMS-P by 8 minutes.

Trial conditions: constant atmospheric boiling, same wort kettle, same brew length, raw material composition, etc.

0 10 20 30 40 50 60 70 80 90 100

Time [min]

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

Conventional

Rel

. DM

S-P

[-]

JETSTAR™

Phase 2Phase 1

6

Always hygienically safeThe JETSTAR ™ allows optimal cleaning. In contrast to systems with circulation pump it enables complete drainage of water and detergents without residues. A short intermediate cleaning during the normal brewing process always ensures constant boiling conditions.

The short program includes pre-rinsing with water, caustic cleaning, neutralizing and post-rinsing with water and takes only 20 minutes. The time involved does not affect the brew cycle time.

Technically superior: the JETSTAR™.

GEA Brewery Systems has been relying on the internal

boiler for wort boiling for a long time now. It offers decisive

advantages over an external boiler. The internal boiler works on

the basis of a purely physical principle: steam bubbles create a

density difference between the wort in the internal boiler and

the kettle, thus ensuring continuous circulation. This principle,

also known as thermosiphoning principle, works without

additional circulation pump and minimizes mechanical stress

on the wort. With internal boilers, wort circulation rates

are much higher than with external boilers. During boiling,

wort is circulated 20 – 30 times per hour, which ensures

a homogeneous temperature throughout the entire wort

kettle. The tube bundle is located right in the middle of

the medium to be heated; it emits heat straight into the

wort and not to the surroundings. With the JETSTAR™,

our innovative design of internal boilers, we achieve better

homogeneity right from the start of wort heating.

Pressure control during Dyn. LPBDepending on whether a vapour condenser is used or not, various methods can be employed to control the pressure. In plants without vapour condensation (see left) we install a bypass pressure control valve in the vapour pipe. When using a vapour condenser, the pressure is controlled via the water feed from the energy storage tank. The water feed is considerably reduced during the pressure build-up phase.

Wort kettle with JETSTAR™

Wort

Fromenergy storage

Toenergy storage

Vapour condenser

Condensate

Wort kettle with JETSTAR™

Wort

7

Efficient evaporation

with the two-level wort spreader

The patented two-level wort spreader distributes the wort

over the wort surface on two different levels. The more

homogeneous flow conditions and the larger surface area

ensure a particularly efficient evaporation of undesired

aromas. At the same time, foam formation on the wort

surface is also significantly reduced.

Two-level wort spreader

Subjet orifice

Cone

Shell and tube heat exchanger

Condensate/Hot waterSteam/Hot water

FACTS & FIGURES:

J More flexible wort boiling technology with two-phase boiling: Thermal conversion processes and evaporation are independent from each other

J Achievement of stationary operating conditions during wort heating

J Homogeneous wort mixing in the wort kettle J Technological flexibility J Easy retrofitting into existing wort kettles J Economical and technological advantages J Energy savings due to low evaporation

GEA Process Engineering

GEA Brewery Systems GmbH Huppmann Tuchenhagen

Locations:

Heinrich-Huppmann-Str. 1, 97318 Kitzingen, Germany Phone +49 9321 303-0, Fax +49 9321 303-603

Am Industriepark 2–10, 21514 Büchen, Germany Phone +49 4155 49-0, Fax +49 4155 49-2770

gea-brewerysystems @ gea.com, www.gea.com JETS

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We live our values.Excellence • Passion • Integrity • Responsibility • GEA-versity

GEA Group is a global engineering company with multi-billion euro sales and operations in more than 50 countries. Founded in 1881, the company is one of the largest providers of innovative equipment and process technology. GEA Group is listed in the STOXX® Europe 600 index.